Model comparison

DeepSeek V4 Flash vs gpt-oss-120b

DeepSeek V4 Flash is the stronger model overall, scoring 53.6 to 36.3 on the Noometry Index. gpt-oss-120b costs 3.7× less per token, which makes it the better buy when DeepSeek V4 Flash's lead doesn't matter for your workload.

Last verified . 31 shared benchmarks.

DeepSeek V4 Flash DeepSeek

53.6

Rank #35 Confirmed

gpt-oss-120b OpenAI

36.3

Rank #217 Confirmed

Summary

  • They share 31 benchmarks with published results for both. DeepSeek V4 Flash scores higher in 8 categories and gpt-oss-120b in 0 categories; 8 gaps are clear of the uncertainty.
  • The widest gap is in reasoning, where DeepSeek V4 Flash leads 53.7 to 20.0.
  • The biggest single-benchmark swing is SimpleBench: 61.1% for DeepSeek V4 Flash and 22.1% for gpt-oss-120b.
  • gpt-oss-120b is cheaper at $0.037 / $0.17 per million input/output tokens, against $0.15 / $0.60 for DeepSeek V4 Flash.
  • DeepSeek V4 Flash accepts more context: 1M tokens versus 131K.

Side by side

DeepSeek V4 Flash and gpt-oss-120b specifications
DeepSeek V4 Flashgpt-oss-120b
ProviderDeepSeekOpenAI
Noometry Index53.636.3
Released2026-04-242025-08-05
WeightsOpenOpen
Context window1M131K
Max output393K41K
Input $ / M tokens$0.15$0.037
Output $ / M tokens$0.60$0.17
Results tracked4148

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Category by category

Coding DeepSeek V4 Flash leads

DeepSeek V4 Flash: 47.9 (#59), gpt-oss-120b: 33.5 (#256)

Coding benchmarks
BenchmarkDeepSeek V4 Flashgpt-oss-120b
SciCode49.9%36%
WeirdML63%48.2%
LMArena Coding14571380
ALE-Bench1,306575.62
FrontierCode18.8%—
SWE-bench Verified (bash only)—26%
Aider Polyglot—41.8%
LMArena WebDev1582—
AlgoTune—1.41

Agentic & Tool Use Not comparable

DeepSeek V4 Flash: —, gpt-oss-120b: 12.2 (#153)

Agentic & Tool Use benchmarks
BenchmarkDeepSeek V4 Flashgpt-oss-120b
Terminal-Bench—18.7%
APEX-Agents—4.4%
METR Time Horizons—56.6%
Vending-Bench 2—-21.53

Reasoning DeepSeek V4 Flash leads

DeepSeek V4 Flash: 53.7 (#30), gpt-oss-120b: 20.0 (#245)

Reasoning benchmarks
BenchmarkDeepSeek V4 Flashgpt-oss-120b
SimpleBench61.1%22.1%
Kagi LLM Benchmark52.2%58.6%
CritPt16.6%1.1%
Chess Puzzles33%20%
LMArena Hard Prompts14441364
Mystery Game Puzzles34%2%
DTBench90.9%76.3%
LMCA41.7%22.1%
Epoch Capabilities Index154.49139.93
ARC-AGI-261.4%—
NYT Connections (extended)89.6%—
ARC-AGI-189%—
Surface Evolver Bench—25%

Math DeepSeek V4 Flash leads

DeepSeek V4 Flash: 60.3 (#37), gpt-oss-120b: 52.5 (#50)

Math benchmarks
BenchmarkDeepSeek V4 Flashgpt-oss-120b
OTIS Mock AIME 2024-202594.4%88.9%
LMArena Math14271389
FrontierMath (Tiers 1-3)57.5%—
FrontierMath Tier 424.4%—
MathArena Final-Answer Competitions76.5%—
ProofBench56%—
Omni-MATH—68.8%

Knowledge DeepSeek V4 Flash leads

DeepSeek V4 Flash: 55.4 (#48), gpt-oss-120b: 42.4 (#96)

Knowledge benchmarks
BenchmarkDeepSeek V4 Flashgpt-oss-120b
GPQA Diamond91%75.8%
LMArena Expert14411356
SimpleQA Verified33.6%—
MMLU-Pro—79.5%
Confabulations—15.7%
Vectara Hallucination Rate—14.2%
GPQA (HELM)—68.4%

Multilingual DeepSeek V4 Flash leads

DeepSeek V4 Flash: 53.0 (#72), gpt-oss-120b: 48.0 (#147)

Multilingual benchmarks
BenchmarkDeepSeek V4 Flashgpt-oss-120b
LMArena Non-English14201351
LMArena Chinese14681385
LMArena French14391369
LMArena German14181353
LMArena Japanese14061331
LMArena Korean13841282
LMArena Russian14281343
LMArena Spanish14361389

Instruction Following DeepSeek V4 Flash leads

DeepSeek V4 Flash: 74.9 (#81), gpt-oss-120b: 69.3 (#173)

Instruction Following benchmarks
BenchmarkDeepSeek V4 Flashgpt-oss-120b
LMArena Instruction Following14211318
IFEval—83.6%

Long Context DeepSeek V4 Flash leads

DeepSeek V4 Flash: 43.8 (#85), gpt-oss-120b: 31.4 (#278)

Long Context benchmarks
BenchmarkDeepSeek V4 Flashgpt-oss-120b
LMArena Longer Query14341319
Fiction.LiveBench—44.4%

Writing & Preference DeepSeek V4 Flash leads

DeepSeek V4 Flash: 63.8 (#61), gpt-oss-120b: 46.5 (#217)

Writing & Preference benchmarks
BenchmarkDeepSeek V4 Flashgpt-oss-120b
LMArena Text14321365
LMArena Creative Writing14031275
EQ-Bench Creative Writing1559961
LMArena Multi-Turn14491340
Short-Story Creative Writing—77.1%
WildBench—84.5%

Frequently asked questions

Is DeepSeek V4 Flash better than gpt-oss-120b?

DeepSeek V4 Flash is the stronger model overall, scoring 53.6 to 36.3 on the Noometry Index. gpt-oss-120b costs 3.7× less per token, which makes it the better buy when DeepSeek V4 Flash's lead doesn't matter for your workload.

Which is cheaper, DeepSeek V4 Flash or gpt-oss-120b?

gpt-oss-120b is cheaper. It lists at $0.037 per million input tokens and $0.17 per million output tokens; DeepSeek V4 Flash lists at $0.15 and $0.60.

Is DeepSeek V4 Flash or gpt-oss-120b better for coding?

DeepSeek V4 Flash scores higher on coding benchmarks: 47.9 versus 33.5 in the Noometry coding category.

Which has the bigger context window?

DeepSeek V4 Flash does, with 1M tokens against 131K.

How many benchmarks do DeepSeek V4 Flash and gpt-oss-120b share?

31 benchmarks have published results for both models. DeepSeek V4 Flash has 41 scored results on Noometry and gpt-oss-120b has 48.

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